This invention relates to a digital audio recording medium and a reproducing apparatus thereof. More particularly, this invention is applied effectively to a recording format of digital audio signals on a high-density recording medium, such as an optical disk, and to a reproducing apparatus for reproducing the high-density recording medium.
In recent years, high-density recording optical disks on which the main picture signal, plural types of sub-picture signals accompanying the main picture signal, and audio signals of plural channels can be recorded have been developed. The high-density recording optical disk is called DVD. Hereinafter, the technique is referred to as DVD video.
On the basis the DVD video technique, the DVD audio technique has been developed. The development of DVD audio has aimed at establishing audio special technology to achieve high sound quality.
In the development of DVD audio, there have been demands toward approaching the standard of DVD audio to the standard of the audio data structure in DVD video. A conventional equivalent relating to DVD audio has been disclosed in, for example, Jpn. Pat. Appln. KOKAI Publication No. 9-312066.
It is, accordingly, an object of the present invention to provide not only a digital audio recording medium capable of realizing a DVD audio standard having a high-sound-quality specification by making the best use of the audio data structure in DVD video, but also a reproducing apparatus for the digital audio recording medium.
The foregoing object is accomplished by providing a recording medium which enables an audio signal digitized at a specific sampling frequency in a specific number of quantization bits to be recorded in a specific area on the recording side, and which comprises: a first sample data string created by digitizing a first one of channel audio signals at a first sampling frequency in a first number of quantization bits; a second sample data string created by digitizing a second one of the channel audio signals at a second sampling frequency in a second number of quantization bits; and header data including timing data to synchronize the first sample data string with the second sample data string, wherein the first sample data string, the second sample data string, and the header data are recorded on the recording medium. The recording medium further comprises means for decoding the data read from the recording medium into plural channel audio signals. Moreover, the recording medium further comprises means for transferring a signal of the above data structure and recording it on a recording medium. Additionally, the recording medium further comprises means for transferring a signal of the above data structure.
Use of those means makes it possible to put all the data transfer rates in a specific data transfer rate range, because the sampling frequency or the number of quantization bits for the first channel audio signal is made different from that for the second channel audio signal. This enables high-quality sound to be obtained in the data transfer rate range complying with the desired standard. Such data as assures high-quality sound can be recorded on the recording medium.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.